Ornithodoros savingyi – the tick vector of Candidatus Borrelia kalaharica in Nigeria

Endemic tick-borne relapsing fever (TBRF) has not been documented in Nigeria, yet clinically compatible cases have been described and soft tick species are endemic in surrounding countries. Consequently, our aim was to investigate if TBRF associated Borrelia were present in Nigeria. To address this, we examined 49 soft tick pools to identify the tick species and screen for Borrelia. The tick species was revealed by 16S 32 rRNA amplification and Sanger sequencing to be Ornithodoros savignyi, an aggressive multi-host rapidly feeding species with significant veterinary impact. We detected Borrelia in three of 49 pooled samples (6%). Molecular analysis of amplified 16S rRNA, flagellin and intragenic spacer fragments disclosed that this Borrelia was synonymous with the recently described Candidatus Borrelia kalaharica described in a tourist returning to Germany from South Africa. Given the widespread endemic range of this tick vector, TBRF should be considered as part of the differential diagnosis in patients with fever returning from arid areas of Africa and further afield.